﻿#region The MIT License (MIT)
// The MIT License (MIT)
// Copyright (c) 2010 - 2013 Sovacode LLC
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated 
// documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or substantial portions
// of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
// BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
// CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#endregion

using System;
using System.Windows.Input;

namespace Sovacode.RubiksCube.Common.Command
{
    /// <summary>
    /// Basic command
    /// </summary>
    /// <typeparam name="T">Type of Parameter</typeparam>
    public sealed class RelayCommand<T> : ITypedCommand<T>
    {
        #region Private Fields

        /// <summary>
        /// The execute action
        /// </summary>
        private readonly Action<T> _execute;
        /// <summary>
        /// The predicate of execute
        /// </summary>
        private readonly Predicate<object> _canExecute;

        /// <summary>
        /// The command type <see cref="CommandType"/>
        /// </summary>
        private CommandType _commandType = CommandType.Normal;

        #endregion

        #region Constructors

        /// <summary>
        /// Initializes a new instance of the <see cref="RelayCommand{T}"/> class.
        /// </summary>
        /// <param name="execute">The execute.</param>
        /// <param name="canExecute">The can execute.</param>
        /// <exception cref="System.ArgumentNullException">execute</exception>
        public RelayCommand(Action<T> execute, Predicate<object> canExecute = null)
        {
            if (execute == null)
            {
                throw new ArgumentNullException("execute");
            }

            _execute = execute;
            _canExecute = canExecute;
        }

        #endregion

        #region ICommand Members

        /// <summary>
        /// Can execute command
        /// </summary>
        /// <param name="parameter">Parameter</param>
        /// <returns>True if can</returns>
        public bool CanExecute(object parameter)
        {
            return _canExecute == null || _canExecute(parameter);
        }

        /// <summary>
        /// Execute
        /// </summary>
        /// <param name="parameter">Parameter</param>
        public void Execute(object parameter)
        {
            Execute((T)parameter);
        }


        /// <summary>
        /// Occurs when changes occur that affect whether or not the command should execute.
        /// </summary>
        public event EventHandler CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }

        /// <summary>
        /// Execute Action with specific parameter type
        /// </summary>
        /// <param name="parameter">Parameter</param>
        public void Execute(T parameter)
        {
            if (!Equals(Parameter, default(T)))
            {
                _execute(Parameter);

                return;
            }

            _execute(parameter);
        }


        #endregion

        #region Public properties

        /// <summary>
        /// Parameter
        /// </summary>
        public T Parameter { get; set; }

        /// <summary>
        /// Command type <see cref="CommandType"/>
        /// </summary>
        public CommandType Type
        {
            get { return _commandType; }
            set { _commandType = value; }
        }

        #endregion
    }
}